Fuel-oil atomizing-burner.



F. C. STARR.- FUEL 0H. ATOMIZING BURNER.

APPLICATION FILED JULY 3.1915.

Patented Man. 12, I918.

t of the pipe or barrel of the burner.

burners in which the fuel is ejected rnn'rcnnn c. 's'rann, or rnrnannnrnim, rnrmsrnvama.

rust-01L ATOMIZING-BURNEE.

Specification oi Letters Patent.

Application filed July 8, 1915. Serial No. 37,818.

To all whom it may concern:

Be it known that I, FLETCHER C. STARR, a citizen of the United States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invente certain new and useful Improvements in Fuel-Oil Atomizing-Burners, of which the following is a specification.

This invention relates to that type of oil from the nozzle of the burner in the form of a finely divided spray. The main objects of my 1nvention are to increase the fineness of atomization, to eliminate the tendency to carbonization in the passages of the burner, to simplify the structure and to provide an absolutely oil-tight protected joint between the cap or nut constituting the tip and the end Another purpose of my invention is to increase the efficiency of burners of the atomizing type the parts traversed by the oil that the atomized particles issue from the nozzle orifice with exceedingly high vortical velocity thereby forming a conical jet having the wide angle of substantially 90.

In'the accompanyi g drawings, Figure 1 is a fragmentary longitudinal sectional view illustrating the manner of connecting a fuel oil burner to a boiler; Figs. 2 and 3 are en-- larged longitudinal sectional views of the atomizing end of a burner embodying my invention; Fig. 4 is a front elevation of the same, partly in section, taken on the line H of Fig. 2; Fig. 5 is a longitudinal section of the floating plug; and Fig. 6 is a longitudinal section of the end nut or burner The tube 1, forming the barrel of the burner is provided with a suitable fitting 3, at one end by which it may be readily attached to the fuel oil supply pipe and at the other end it is externally threaded at 5, to receive the nut or burner tip 8. The tube may be notched or flattened at 6, to receive a wrench. The end of the tube 1 is accurately ground at the proper angle to fit the inner front wall of the recess in the nut or cap 8, which is also accurately ground, to

form an oil-tight oint within the inclosure by decreasing the frictional resistances with- The forward end 12 in the burner passages and so coordinating.

cal face 12 of t of the nut. This protected oil-tight joint performs an important function in preventing any leakage of the high oil pressure so that no oil can escape and follow along the threads 5. The joint being upon the interior of the nut cavity is thoroughly protected from injury or corrosion.

The bore 10 of the barrel 1 is enlarged at the burner end into a recess 10, to form a chamber for the floating plug 12. As shown in Fig. 5, the plug is provided with a central longitudinal passage 14, extending inwardly from the rear end and intersecting a transverse passage 15. The forward end of they plug is frusto-conical and is accurately ground along the annular inclined face 12 to fit the inner front face 8, of the recess in the nut 8. The flattened portion 12 of the plug forms the rear wall of a central cylindrical recess 18, cut in the front wall of the recess in the nut and is of the same diameter. of the cylindrical body of the plug or distributing head is of reduced diameter to provide an enlarged annular space tion with the fuel. passage 15, and this an nular space communicates with the chamber 18. by means of grooves 19, cut into the coni e plug. These grooves are tangential to the circular rim of the flat ortion 12 and consequently to the annular wall of the'chamber-18, and form depth and cross-section throughout their length. j

In operation when the oil pressure supply is turned into the burner tube, the plug '12 which lies upon the lower side of the chamber 10? shown in Fig.3, is lifted by the ve locity pressure of the oil into the central floating position illustrated in Fig. 2, the forward conical face being firmly pressed against the interior conical wall of the nut. The oil flowing through the passages 14 and. 15 into the annual space around the plug, traverses the channels formed by the grooves 19, and enters tangentially 18 under great pressure so that a violent whirling motion is set up which separates the oil into exceedingly fineparticles, and in this form it is forced outwardly toward the nozzle orifice 20. In order that there may be no throttling or undue loss of pressure in,

Patented Mar. 12,1918,

within the chamber 10? in communica-' into the chamberare cut of unipassing through the grooved channels, I make these grooves of uniform depth and cross-section.

' I havediscovered that the degree of an- 5 gularity or obliquity at which thetangent1a1 streams enter the whirling chamber 18,

- enhances or detracts from the centrifugalenergy imparted to the oil and upon which thefineness of the disrupted or separated 10.

adjacent the orificeis about 45, so that the,

longitudinal and transverse components of the stream with respect to the axis of the burner are equal. I have discovered that the velocity energy transmitted into centrifugal effort can be greatly enhanced by increasing thetransverse component over the longitudinal component until the obliquity of the grooved chanenls 19 enters the whirling chamber atan angle. of about 30 from a transverse axis or 60 from the axis of the burner as indicated .in the grooves are cut tangentially to the -circum erence of the chamber 18 and do not follow the elements of the conical surface, these grooves are at an angle of 26 to the transverse axis as indicated in Fig. 2.

I have also discovered that the amount of centrifugal energy which can be transmitted with the particles as they ass through the nozzle orifice is greatly affected b the configuration of the front wall 0 the whirling chamber. If this front wall were perpendicular to the orifice where the latter intersected said wall, much of the ve locity of the whirling particles would be expen edin eddies. I therefore bevel or conically taper the forward wall of the whirltoward the orifice into mg chamber at 18 which it merges. This reduces the frictional resistance and the constant-pressure velocityof the inrushing streams crowds the rapidly whirling particles along. the converging walls 18 from the'outer margins of the chamber 18, where the rotary velocity is greatest, thereby causing these particles to rush into the orifice wlth an exceedingly rapid vortical motion which instantly separates the particles intowidely divergent of the nozzle. This results, therefore, in producing an atomized jet in the form of exceedingly minute particles forming a mist extending over a cone having an angle of about 90, as indicated in Fig. 1. I have discovered that the obliquity of the sides 18 of the whirling chamber less from the longitudinal axis then the into the position shown in Figs. 5 and 6. Since eliminates the danger of .sonlcal paths as they emerge from the mouth should diverge obliquity of the grooved channels 19 lead ing into the chamber 18 in .order to produce the maxlmum torsional velocity through the orifice and the consequent divergence of the of the spray and conical jet and attenuation that this angle should be approximately 45 as shown in Fig. 6.

One of the inherent defects in atomizing f fuel burners is tendency oil that remains in the small channels as soon as the pressure is withdrawn and espeof a joining burners while it is cut off. The passages thus become clogged to carbonize any ciall if the burner is subjected to the heat so that they I requlre cleaning before the burner can be used. I have overcome this defect by proshown in Fig. 2, by the velocitypressure of Y the oil passing therethrough, but the instant the oil supply is shut oil, the plug drops end face causing it to slide back from the inner front wall 8*, frontwall of the channels 19, and thus per- Fig. 3, the conical .viding means for automatically draining the which constitutes the mitting any oil entrapped therein to run:

down into the lower part of the recess in the nut, In the practical operation of this burner I have found that'a burner may be shut oil and then exposed to the heat of the other burners under the boiler withoutbecoming carbonized and may be thrown into and out of use repeatedly without cleaning or other attention.

The simplicity of my atomizing burner,

consisting of the tube, nut and loose plug,

getting out of order incident to more complicated structures which require springs and parts demanding special adjustment. 9

The protected oil-tight joint between the ground interior face of the recessed cap nut and the end of the tube provides an oil-tight passage from the bore of the tube to the nozzle orifice and also prevents any leak along the threads of the nut and eliminates joints that are exposed to the corrosive action of the flame in the intensely heated zone under the boiler, which is a very important feature in burners of this type operating under pressures varying from toover 200 lbs. Burners constructed in accordance with my present invention'are now being operated pressures. v

The angles of entrance and of exit of the about 40 lbs.

under the last mentioned oil passages connected to'the atomizing or whirling chamber 18 are so correlated that the maximum centrifugal velocity is concentrated in the vortical stream of particles passing into the orifice 20,

which results in j a I larged a recessed an expansive force at'the. fice causing separate into cal path extending across an arc of 90. In fact, owing to this great expansive force and to the rapidity of the rotation in the whirling chamber, the issuing jet forms an attenuated mist without the concentrate in drops, so that the resulting combustion is complete.

As previously pointed out, the recedingmotion of the floating plug upon the withdrawal of the oil pressure, automatically opens the oil passages leading to the whirlin chamber along one side of their entire extent, thereby causing any entrapped oil to drain and preventing the carbonization which has heretofore caused trouble whenever a dead burner. was exposed to the heat of the other burners. This feature also enables my burner to operate successfully with the heavy oils. V

I have described in detail the construction illustrated in the accompanying drawings to disclose a specific embodiment-of my invention but I am awarethat various changes may be made therein within the scope of my claims. I claim I 1. A fuel oil burner, comprising a barrel adapted to be connected with a. fuel "supply and having the bore at the outlet'end ennut threaded upon said end and provided with a discharge orifice,

and a loose or floating plug in said enlarged portion of the bore havlng a series of channels cut in its outer end forming fuel-passages connecting the annular space aroun the plug and the orifice and also provided with passages terminating in space and communicating with the bore of the barrel.

and having the bore at the outlet'end*en-' larged, a recessed nut threaded upon said end and provided with a cylindrical chamberv and a discharge from, and a loose or floating plug 1n said enlargedportion of the bore having a series of channels cut in its outer end forming fuel passages connecting the annular space around the plugand said chamber and also provided with internal passages connecting said annular space and the bore of'the bar- 1'6 3. A fuel oil burner, comprisingga barrel adapted to be connected with a fue supply and having the bore at the outlet-end enlarged, a recessed nut threaded upon said end and provided with a'discharge orifice, the inner wall of said recessed nut and the end of said barrel having ground surfaces engaging to form an oil-tight joint, and a mouth of t eta-:7 the finely divided partielesfto the unusually divergent coni-lf usual tendency to a fuel supply and of said inner wall, and a said annular" r the plug is actuated by 2. A fuel oil burner, comprislng a'barrel, adapted to be connected with a fuel supply cut in its conical gential to the peripheryof said chamber, an

orifice leading theredistributing head within said enlarged portion of the bore having a plurality of anguflarly disposed channels in the outer end thereof connecting with the annular space surrounding said head, and an internal channel terminating in said annularvspace and communicating with the bore of the barrel.

4. A fuel oil burner, comprising a barrel having a bore adapted to be connected with exteriorly threaded at the burner end, a recessed nut engaging said threaded end and provided with a discharge 7 of said recessed nutsaid tapering the inner wall toward said orifice,

and the end of said barrel having engaging to form an oila distributing head within orifice, tapering inner wall ground surfaces tight joint, and the bore of the face corresponding with the taper of sa1d inner wall and provided with a plurality of passages connecting the surrounding annu- 'lar space with said orifice and angularly disposed to oil passing impart a rotary motion to the therethrough, and an internal passage terminating in said annular space.

5. A fuel oil burner, comprising atbarrel adapted to be connected at supply, a recessed form a cap over the mouth of the barrel, and formed with a discharge orifice and with a cylindrical whirling chamber opening thereinto, the inner wall of said'recessed nut tapering and converging into therear end of said chamber and having a round surface forming a seat, thegforward end of \said chamber tapering'toward said orifice but with less obliquity than the taper floating plug fitting loosely within the barrel having a frusto-conical end the conical part of which is adapted'to bear against said seat when fuel pressure, and the plane portion forming the rear wall of said whirling chamber, said plug having surface and disposed tanformed with a discharge orifice and with a cylindrical whirling chamber opening therelnto, the inner wall of said rechannels barrel having a conical end one end to a fuel nut threaded to the other the mouth of the cessed nut converging toward the rear end,

of said chamber and forming an annular conical seat around its periphery and a fioating plug fitting loosely within thebore of the barrel having a frusto-conical end the conical part of which is adapted to bear; against said seat when the plug is centrally" held by the velocity pressure of the fuel, said plug having grooves cut into said conical end surface the open sides of which are closed by a said conical seat, when the A into central posltion by the 5 and are automatically opened ping of the plug when the pr thereby permitting s:

drawn, drain, the forward portion of ing a smallendiameter than 10'portion thereof to form an plug is lifted fuel pressure by the dro essure is wit rid grooves to said plug hav-' the remaming enlarged surrounding annular chamber and bein provided with assages terminating in sald annular cham er.

In testimon, whereof I afiix in presence 0 two witnesses.

Witnesses:-

W. H. LEE, S. C.

my signature FLETCHER C STARR. 

